1. Field of the Invention
This invention relates to poly(carbosilane) copolymers and methods of making the same.
2. Discussion of Relevant Art
Poly(methylhydrosiloxanes) having repeating units of the formula: ##STR2## are well known. They can be prepared by hydrolysis of methyldichlorosilane or acid catalyzed ring opening polymerization of sym-tetramethylcyclotetrasiloxane. Poly(methylhydrosiloxanes) contain reactive hydride groups bound to the silicon atoms. The poly(methylhydrosiloxanes) can be crosslinked to produce elastomeric products or reacted with unsaturated monomers to yield graft copolymers.
It is also known that poly(dimethylsilane) fibers can be pyrolytically converted into silicon carbide fibers. In S. Yajima et. al., J. Mater. Sci. 13, 2569 (1978), it is proposed that poly(methylsilylene methylene) having repeating units of the formula: ##STR3## is an intermediate in the formation of the silicon carbide fibers by this process.
The anionic polymerization of (4-vinylphenyl)dimethylsilane to produce poly[(4-vinylphenyl)dimethylsilane] is described in Hirao, A. et. al., Macromolecules 1987, 20, 1505. This anionic addition polymerization of carbon-carbon double bonds of (4-vinylphenyl)dimethylsilane produces polymers having repeating units of the formula: ##STR4##
The preparation of poly(1,1 dimethyl-1-silapent-3-ene) by the metathesis ring-opening polymerization of 1,1-dimethyl-1-silacyclopent-3-ene using a WCl.sub.6 /Na.sub.2 O.sub.2 /Al(isoBu).sub.3 catalyst system is disclosed in Lammens, H. et. al., Pol. Let. 1971, 9 341 and Finkel'shtein, E. Sh. et. al., Izvestiva Akademii Nauk SSSR, Seriya Khimicheskaya 1981, 3, 641. The preparation of poly(1,1-dimethyl-1-silapent-3-ene) and poly(1-1-diphenyl-1-silapent-3-ene) from 1,1-dimethyl-1-silacyclopent-3-ene and 1,1-diphenyl-1-silacyclopente-3-ene, respectively, by anionic ring-opening polymerization using butyllithium as a catalyst is disclosed in Horvath, R. H.; Chan, T. H., J. Org. Chem. 1971, 20, 4498. Anionic polymerization of 1-methyl-1-silacyclopent-3-ene to form a homopolymer is described in Macromolecules 23, 1915 (1990) and "Anionic Ring Opening Polymerization of 2-Methyl-2-Silaindan. Characterization of the Polymer and Mechanism of Polymerization" by S. Q. Zhou, et al and in Makromolekulare Chemie Rapid Communications, 11, 19-24 (1990) by S. Q. Zhou et al.